I use mac High Sierra, and download a Fusion Professional 10.0.1 for 30 days trial version. I continuously get "can not find a valid peer process to connect to" notification, when I try to install any OS from image.

As I wrote in that article, if the kernel extensions block does not show up in "Security & Privacy" in macOS then most likely you can force it to show up by moving the Fusion install to another location using Finder.

Eg. Move your Fusion install from Applications to Desktop and back again.

Then check again in "Security & Privacy" and hopefully the kernel extension blockage is listed there now that so you can allow it.

I had the same problem, although I was using an already installed High Sierra, and a brand new, never installed Fusion 10.0 Pro. As the author suggested, I went into the Mac's Security preferences and it specifically told me it was blocking Fusion, so I unblocked it ... and after a bit of futzing to get it to work like I want, it's working fine.

Just out of curiosity, why would different solutions work for different OS' s relating to the same error when all you gotta do is disconnect network adapter when booting VM. I always found this solves the issue, so will continue to use this method until it fails for me.

I upgraded to Fusion 10.0.1 (from 8.x) and started getting this message when I started VMs. The warning and button never appeared in my "Security and Privacy" screen. Suddenly at some point it appeared, I clicked "Allow" and I was off.

Now today I'm getting the same error and the message/button are not appearing again.

The other potential problem is running out of device slots. This is true with osxfuse on High Sierra, I had to unload the virtual box app and I have an expressvpn.tun that is stuck there and takes a slot, but this error looks like a problem with signing. Sigh. any ideas?